1. Field of Invention
The field of this invention relates to computer security systems for preventing unauthorized changes to computer files stored on a long-term rewritable memory storage device.
2. Description of Prior Art
Computers have become very common and have advanced greatly in recent years. However, there still remains the problem of viruses, worms and other malicious programs that can disable a computer and damage files on long-term storage devices. As we have found in recent years, it is almost impossible to prevent malicious programs from finding their way onto our computers. New and more dangerous viruses and worms are appearing almost daily. To solve this problem, the disclose invention attacks the problem in a completely different way than security systems before it. Instead of trying to prevent malicious programs from entering the computer, the disclosed system focuses on preventing damage to long-term memory devices attached to the computer. The system allows programs, even malicious programs to execute on the computer, but long-term storage can be protected. Thus, once the computer is turned-off or re-booted, all changes that the malicious program appeared to make are quarantined, and do not effect the computer again unless the user actually executes the malicious program again. The disclosed security system functions by segregating (quarantining) each program and/or program thread within their own associated group or folder. However, this “quarantine” is unlike any such quarantine before it, because programs can still load, execute, modify and save any file on the hard drive for its own use. In this way, programs (executable files) can operate without restriction with their own files and data, unaware that they are unable to make lasting changes to files on the long-term memory storage device that are not part of its associated group and/or within its storage folder. Thus programs operate in a partially-virtual computer space (i.e. alias files and/or alias folders) when trying to modify and saving other program's files to the long-term storage device. From the program's point of view, it can always operating in “real” computer space, but in fact, it may be operating in a virtual space with alias files and not be aware of it. The terms alias directories (alias folders) and alias files will be used to distinguish these files and folder from the virtual directories and virtual folders which Windows operating system already uses and are different from the disclosed security system using alias directory address system. Thus, to avoid confusion the term “alias directories”, “alias folders” and “alias files” will be used throughout the remainder of this patent to describe the alternate folders and files generated for security purposes by the disclosed security system.
Program Directories are another type of virtual directory used by the disclosed security system. Program directories are a dynamically generated directory for specific programs at the time they access the long-term storage device. Depending on which program is accessing the storage device, what file is being accessed and what type of access is requested, a different Program Directory can be generated that the Program believes is the “Real” or “Absolute” directory.